U.S. patent application number 15/761472 was filed with the patent office on 2018-09-20 for sensor assembly for a sensor, sensor, as well as measuring system formed therewith.
The applicant listed for this patent is Endress + Hauser Flowtec AG. Invention is credited to Christian Lais, Andreas Strub, Dominique Wiederkehr.
Application Number | 20180266857 15/761472 |
Document ID | / |
Family ID | 56920697 |
Filed Date | 2018-09-20 |
United States Patent
Application |
20180266857 |
Kind Code |
A1 |
Lais; Christian ; et
al. |
September 20, 2018 |
SENSOR ASSEMBLY FOR A SENSOR, SENSOR, AS WELL AS MEASURING SYSTEM
FORMED THEREWITH
Abstract
A sensor assembly comprises a deformation body having two
oppositely lying surfaces and an outer edge segment as well as a
sensor blade extending from the surface to a distal end and having
a left side, first lateral surface and a right side, second lateral
surface. An overload protection apparatus extending from the edge
segment to a distal end for protecting the deformation body against
plastic, i.e. irreversible, deformation and having a support
stirrup led with lateral separation around the sensor blade as well
as two stops held by the support stirrup for limiting movement of
the sensor blade, of which a first stop is located on the left side
of the sensor blade and a second stop is located on the right side
of the sensor blade. The stops are so dimensioned and arranged that
an intermediate space formed therebetween receives only a portion
(112a) of the sensor blade. The deformation body and the sensor
blade are additionally adapted to be excited to execute
oscillations about a shared static resting position and, in such
case, to be moved relative to the overload protection apparatus, in
such a manner that the sensor blade executes pendulum-like
movements elastically deforming the deformation body. A sensor
formed by means of such a sensor assembly as well as a transducer
element coupled therewith and serving for generating a sensor
signal representing movements of the sensor blade changing as a
function of time and/or deformations of the deformation body
changing as a function of time, and a measuring system formed by
means of the sensor and a measuring electronics connected therewith
can be used for registering pressure fluctuations in a flowing
fluid, such as, for instance, a vapor or steam, at least at times
having a temperature of 400 C and/or at least at times a pressure
of greater than 140 bar, for instance, in order to measure flow
parameters of the fluid.
Inventors: |
Lais; Christian;
(Munchenstein, CH) ; Strub; Andreas; (Weil am
Rhein, DE) ; Wiederkehr; Dominique;
(Hagenthal-le-bas, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Endress + Hauser Flowtec AG |
Reinach |
|
CH |
|
|
Family ID: |
56920697 |
Appl. No.: |
15/761472 |
Filed: |
September 8, 2016 |
PCT Filed: |
September 8, 2016 |
PCT NO: |
PCT/EP2016/071147 |
371 Date: |
March 20, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01F 1/3209 20130101;
G01F 1/3263 20130101; G01F 15/10 20130101 |
International
Class: |
G01F 1/32 20060101
G01F001/32; G01F 15/10 20060101 G01F015/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 24, 2015 |
DE |
10 2015 116 147.8 |
Claims
1-31. (canceled)
32. A sensor assembly for a sensor, which sensor assembly
comprises: a deformation body, especially a membrane like and/or
disk shaped deformation body, exhibiting a first surface, an
oppositely lying, second surface, especially a second surface at
least partially parallel to the first surface, and an outer edge
segment; a sensor blade extending from said first surface of said
deformation body to a distal end, exhibiting a left side, first
lateral surface and a right side, second lateral surface; and an
overload protection apparatus extending from said outer edge
segment of the deformation body to a distal end and serving for
protection of said deformation body against plastic, deformation,
said overload protection apparatus including a support stirrup led
with lateral separation around said sensor blade and said overload
protection apparatus including two stops held by said support
stirrup for limiting movement of said sensor blade, of which a
first stop is located on the left side of said sensor blade, and a
second stop is located on the right side of said sensor blade,
wherein: said stops are so dimensioned and arranged that an
intermediate space formed therebetween receives only a portion of
said sensor blade; said deformation body and said sensor blade are
adapted to be excited to execute oscillations about a shared static
resting position and, in such case, to be moved relative to said
overload protection apparatus, in such a manner that the sensor
blade executes pendulum-like movements elastically deforming the
deformation body, in the case of which the portion of said sensor
blade located within the intermediate space is moved alternately to
the left, namely in the direction toward said first stop, and to
the right, namely in the direction toward said second stop.
33. The sensor assembly as claimed in claim 32, wherein: said
overload protection apparatus has a connecting element, especially
an annular connecting element, on one end facing said edge segment
of said deformation body.
34. The sensor assembly as claimed in claim 33, wherein: said
connecting element as well as said support stirrup are integral
components of one and the same monolithic, formed part.
35. The sensor assembly as claimed in claim 33, wherein: said
support stirrup and connecting element are connected together,
especially by material bonding, especially welded together.
36. The sensor assembly as claimed in claim 33, wherein: a
connecting element of said overload protection apparatus and said
outer edge segment of said deformation body are connected together,
especially by material bonding, especially welded together.
37. The sensor assembly as claimed in claim 32, wherein: said
deformation body, said sensor blade and said overload protection
apparatus are so dimensioned and arranged that, in the case of said
sensor blade located together with said deformation body in a
shared static resting position, said sensor blade contacts neither
said support stirrup nor either of said stops.
38. The sensor assembly as claimed in claim 32, wherein: said
deformation body, said sensor blade and said overload protection
apparatus are so dimensioned and arranged that, in the case of said
sensor blade together with said deformation body located in a
shared static resting position, gaps are formed between said sensor
blade and each of said two stops, especially in such a manner that
each of the gaps has a minimum gap breadth, which is greater than
0.02 mm and/or less than 0.2 mm, and/or that said sensor blade
contacts neither of said stops.
39. The sensor assembly as claimed in claim 32, wherein: said
deformation body, said sensor blade and said overload protection
apparatus are so dimensioned and arranged that, in the case of said
sensor blade together with said deformation body located in a
shared static resting position, a gap is formed between said sensor
blade and said support stirrup, especially in such a manner that
the gap has a minimum gap breadth, which is greater than 0.02 mm,
and/or that said sensor blade is not contacted by said support
stirrup.
40. The sensor assembly as claimed in claim 32, wherein: said
deformation body, said sensor blade and said overload protection
apparatus are so dimensioned and arranged that, in the case of said
sensor blade together with said deformation body located in a
shared first end position differing from the shared static resting
position, said sensor blade contacts said first stop, but,
especially, does not contact said support stirrup.
41. The sensor assembly as claimed in claim 40, wherein: said
deformation body, said sensor blade and said overload protection
apparatus are so dimensioned and arranged that, in the case of said
sensor blade together with said deformation body located in a
shared second end position differing from the shared static resting
position, as well as also from the shared first end position, the
sensor blade contacts said second stop, but, especially, does not
contact said support stirrup.
42. The sensor assembly as claimed in claim 41, wherein: said
deformation body, said sensor blade and said overload protection
apparatus are so dimensioned and arranged that both a deformation
of said deformation body corresponding to the first end position as
well as also a deformation of said deformation body corresponding
to the second end position are elastic, especially
linearly-elastic.
43. The sensor assembly as claimed in claim 32, wherein: sensor
blade has a projection, especially a terminal and/or pin-shaped
projection; and said deformation body, said sensor blade and said
overload protection apparatus are so dimensioned and arranged that
said projection protrudes inwardly into the intermediate space
formed between said stops.
44. The sensor assembly as claimed in claim 43, wherein: said stops
are provided by edge segments of a recess in said support stirrup,
especially a recess formed as a passageway or bore, and said
intermediate space is formed by a lumen of the recess surrounded by
said edge segments.
45. The sensor assembly as claimed in claim 32, wherein: said
deformation body and said overload protection apparatus are
connected together by material bonding, especially welded, brazed
or soldered together; and/or said deformation body and said sensor
blade are connected together by material bonding, especially
welded, brazed or soldered together.
46. The sensor assembly as claimed in claim 32, wherein: said
overload protection apparatus is composed at least partially,
especially predominantly or completely, of a metal, especially a
stainless steel, or a nickel based alloy; and/or said deformation
body and said overload protection apparatus are composed of the
same material; and/or said deformation body and said overload
protection apparatus are components of one and the same,
monolithic, formed part for example, a casting or manufactured by
3D laser melting.
47. The sensor assembly as claimed in claim 32, wherein: said
support stirrup is led at least partially on a left side of said
sensor blade; and/or said support stirrup is led at least partially
on a right side of said sensor blade; and/or said support stirrup
is led at least partially on a front side of said sensor blade;
and/or said support stirrup is led at least partially on a rear
side of said sensor blade; and/or said overload protection
apparatus is formed by means of a single, monolithic, formed part;
and/or said first stop, said second stop as well as said support
stirrup are integral components of one and the same monolithic,
formed part; and/or said stops are at least partially formed by
edge segments of a recess provided in said support stirrup; and/or
said intermediate space is at least partially formed by a lumen of
a recess provided in said support stirrup.
48. The sensor assembly as claimed in claim 32, wherein: said outer
edge segment is adapted to be connected, especially by material
bonding and/or hermetically sealed, to a seat serving for mounting
said deformation body on a wall of a tube, especially in such a
manner that said deformation body covers, especially hermetically
seals, an opening provided in the wall of the tube and/or in such a
manner that the first surface of said deformation body faces a
lumen of the tube, such that said sensor blade protrudes inwardly
into the lumen; and/or at least one sealing surface, especially a
surrounding and/or annular like sealing surface, is embodied in
said outer edge segment.
49. The sensor assembly as claimed in claim 32, wherein: said
deformation body is composed at least partially, especially
predominantly or completely, of a metal, especially a stainless
steel, or a nickel based alloy; and/or said sensor blade is
composed at least partially, especially predominantly or
completely, of a metal, especially a stainless steel, or a nickel
based alloy; and/or said deformation body and said sensor blade are
composed of the same material; and/or said deformation body and
said sensor blade are components of one and the same monolithic,
formed part, for example, a casting or manufactured by 3D laser
melting.
50. The sensor assembly as claimed in claim 32, wherein: said
support stirrup is U-shaped.
51. The sensor assembly as claimed in claim 32, wherein: said
support stirrup is V-shaped.
52. The sensor assembly as claimed in claim 32, wherein: said
support stirrup is L-shaped.
53. A sensor for registering pressure fluctuations in a flowing
fluid, especially for registering pressure fluctuations in a Karman
vortex street formed in the flowing fluid, which sensor comprises:
a sensor assembly having: a sensor assembly for a sensor, which
sensor assembly comprises: a deformation body, especially a
membrane like and/or disk shaped deformation body, exhibiting a
first surface, an oppositely lying, second surface, especially a
second surface at least partially parallel to the first surface,
and an outer edge segment; a sensor blade extending from said first
surface of said deformation body to a distal end, exhibiting a left
side, first lateral surface and a right side, second lateral
surface; and an overload protection apparatus extending from said
outer edge segment of the deformation body to a distal end and
serving for protection of said deformation body against plastic,
deformation, said overload protection apparatus including a support
stirrup led with lateral separation around said sensor blade and
said overload protection apparatus including two stops held by said
support stirrup for limiting movement of said sensor blade, of
which a first stop is located on the left side of said sensor
blade, and a second stop is located on the right side of said
sensor blade, wherein: said stops are so dimensioned and arranged
that an intermediate space formed therebetween receives only a
portion of said sensor blade; said deformation body and said sensor
blade are adapted to be excited to execute oscillations about a
shared static resting position and, in such case, to be moved
relative to said overload protection apparatus, in such a manner
that the sensor blade executes pendulum-like movements elastically
deforming the deformation body, in the case of which the portion of
said sensor blade located within the intermediate space is moved
alternately to the left, namely in the direction toward said first
stop, and to the right, namely in the direction toward said second
stop; as well as a transducer element for generating a sensor
signal, especially an electrical or optical, sensor signal,
representing movements of said sensor blade changing as a function
of time, especially at least at times periodic movements of said
sensor blade, and/or deformations of said deformation body changing
as a function of time, especially at least at times periodic
deformations of said deformation body.
54. The measuring system for measuring at least one flow parameter,
especially a flow parameter changeable as a function of time,
especially a flow velocity and/or a volume flow rate, of a fluid
flowing in a pipeline, which measuring system comprises: a sensor
for registering pressure fluctuations in the flowing fluid,
especially for registering pressure fluctuations in a Karman vortex
street formed in the flowing fluid having: a sensor for registering
pressure fluctuations in a flowing fluid, especially for
registering pressure fluctuations in a Karman vortex street formed
in the flowing fluid, which sensor comprises: a sensor assembly
having: a sensor assembly for a sensor, which sensor assembly
comprises: a deformation body, especially a membrane like and/or
disk shaped deformation body, exhibiting a first surface, an
oppositely lying, second surface, especially a second surface at
least partially parallel to the first surface, and an outer edge
segment; a sensor blade extending from said first surface of said
deformation body to a distal end, exhibiting a left side, first
lateral surface and a right side, second lateral surface; and an
overload protection apparatus extending from said outer edge
segment of the deformation body to a distal end and serving for
protection of said deformation body against plastic, deformation,
said overload protection apparatus including a support stirrup led
with lateral separation around said sensor blade and said overload
protection apparatus including two stops held by said support
stirrup for limiting movement of said sensor blade, of which a
first stop is located on the left side of said sensor blade, and a
second stop is located on the right side of said sensor blade,
wherein: said stops are so dimensioned and arranged that an
intermediate space formed therebetween receives only a portion of
said sensor blade; said deformation body and said sensor blade are
adapted to be excited to execute oscillations about a shared static
resting position and, in such case, to be moved relative to said
overload protection apparatus, in such a manner that the sensor
blade executes pendulum-like movements elastically deforming the
deformation body, in the case of which the portion of said sensor
blade located within the intermediate space is moved alternately to
the left, namely in the direction toward said first stop, and to
the right, namely in the direction toward said second stop; as well
as a transducer element for generating a sensor signal, especially
an electrical or optical, sensor signal, representing movements of
said sensor blade changing as a function of time, especially at
least at times periodic movements of said sensor blade, and/or
deformations of said deformation body changing as a function of
time, especially at least at times periodic deformations of said
deformation body; as well as a measuring electronics, which is
adapted to receive and to process the sensor signal, especially to
generate measured values representing said at least one flow
parameter.
55. The measuring system as claimed in claim 54, further
comprising: a tube insertable into the course of the pipeline and
having a lumen, which is adapted to convey the fluid flowing in the
pipeline, wherein: said sensor is inserted into the tube in such a
manner that the first surface of said deformation body faces the
lumen of the tube and said sensor blade protrudes inwardly into the
lumen.
56. The measuring system as claimed in claim 54, further
comprising: a tube insertable into the course of the pipeline and
having a lumen, which is adapted to convey the fluid flowing in the
pipeline, wherein: an opening is embodied in the wall of the tube,
especially an opening having a seat serving for mounting said
deformation body on the wall; and said sensor is inserted into the
opening in such a manner that said deformation body covers,
hermetically seals, the opening and the first surface of said
deformation body faces the lumen of the tube, such that said sensor
blade protrudes inwardly into the lumen.
57. The measuring system as claimed in claim 56, wherein: the
opening has a seat serving for mounting said deformation body on
the wall.
58. The measuring system as claimed in claim 57, wherein: at least
one sealing surface is embodied in the seat, especially a
surrounding and/or annular like, sealing surface.
59. The measuring system as claimed in claim 58, wherein; at least
one sealing surface is embodied in the edge segment, especially a
surrounding and/or annular like, sealing surface; and said sealing
surface and the sealing surface of the seat are adapted for
hermetically sealing the opening, especially also with at least one
seal interposed.
60. The measuring system as claimed in claim 55, wherein: said
sensor blade has a length, measured as a minimum distance between a
proximal end of said sensor blade, namely an end bordering on said
deformation body, and a distal end of said sensor blade, namely an
end remote from said deformation body, i.e. its surface, which
length is less than 95% of a caliber (DN) of the tube and/or
greater than half of the caliber (DN); and/or said overload
protection apparatus has a length, measured as a minimum distance
between a proximal end of said overload protection apparatus,
namely an end bordering on said deformation body, and a distal end
of said overload protection apparatus, namely an end remote from
said deformation body, i.e. its surface, which length is less than
95% of a caliber (DN) of the tube and/or greater than half of the
caliber (DN).
61. The measuring system as claimed in claim 54, further
comprising: a bluff body arranged in the lumen of the tube and
adapted to bring about a Karman vortex street in the flowing
fluid.
62. The use of a measuring system as claimed in claim 54, for
measuring a flow parameter--especially a flow velocity and/or a
volume flow rate and/or a mass flow rate--of a fluid, especially a
vapor or steam, flowing in a pipeline, especially a fluid having at
least at times a temperature of greater than 400.degree. C. and/or
at least at times acting with a pressure of greater than 140 bar on
the deformation body and/or the sensor blade of the sensor.
Description
[0001] The invention relates to a sensor assembly having a
deformation body, especially a membrane like and/or disk shaped
deformation body, as well as a sensor blade extending from a
surface of the deformation body. Furthermore, the invention relates
to a sensor formed by means of such a sensor assembly, and to a
measuring system formed with the sensor, and to its application for
registering pressure fluctuations in a flowing fluid and/or for
measuring at least one flow parameter of a fluid flowing in a
pipeline.
[0002] Often used in process measurements--and automation
technology for measuring flow velocities of fluids flowing in
pipelines, especially rapidly flowing, and/or hot, gases and/or
fluid flows of high Reynolds number (Re), or of volume--or mass
flow rates with corresponding flow velocities (u) are measuring
systems embodied as vortex flow measuring devices. Examples of such
measuring systems are known from, among others, US-A 200610230841,
US-A 2008/0072686, US-A 2011/0154913, US-A 2011/0247430, U.S. Pat.
No. 6,003,384, U.S. Pat. No. 6,101,885, U.S. Pat. No. 6,352,000,
U.S. Pat. No. 6,910,387 or U.S. Pat. No. 6,938,496 and are, among
others, also offered by the applicant, for example, under the
designations "PROWIRL D 200", "PROWIRL F 200", "PROWIRL O 200",
"PROWIRL R 200".
[0003] Such measuring systems involve a bluff body protruding into
the lumen of a pipeline in the form, for example, of a component of
a heat supply network or a turbine circulatory system, or into a
lumen of a measuring tube installed in the course of the pipeline.
The bluff body is flowed against by the fluid, resulting in
vortices aligned to form a so-called Karman vortex street within
the volume portion of the fluid flowing directly downstream of the
bluff body. The vortices are, as is known, generated on the bluff
body with a shedding rate (1/fv.sub.tx) dependent on the flow
velocity of the fluid flowing in a principal flow direction through
the measuring tube.
[0004] Furthermore, the measuring systems have a sensor integrated
in the bluff body, or connected with such or protruding downstream
of the same, namely into the region of the Karman vortex street,
into the flow, consequently into the lumen of the measuring tube.
The sensor serves to register pressure fluctuations in the Karman
vortex street formed in the flowing fluid and to transduce such
into a sensor signal representing the pressure fluctuations, namely
to deliver a signal--, for example, an electrical or
optical--signal, which corresponds to a pressure reigning within
the fluid and subjected to periodic fluctuations as a result of
vortices of opposites sense moving downstream of the bluff body.
The sensor signal has a signal frequency (.about.fv.sub.tx)
corresponding to the shedding rate of the vortices.
[0005] The sensor includes a sensor assembly formed by means of a
deformation body--most often formed as a thin and essentially flat
membrane--as well as a sensor blade--most often a plate-shaped, or
wedge shaped, sensor blade--extending from an essentially planar
surface of the deformation body and adapted to register pressure
fluctuations in the Karman vortex street acting in a detection
direction transverse to the actual principal flow direction, namely
to transduce such into movements of the deformation body
corresponding to the pressure fluctuations, in such a manner that
the sensor blade, as a result of the pressure fluctuations,
executes pendulum-like movements in the detection direction, which
deform the deformation body elastically, whereby deformation body
and sensor blade are excited to execute forced oscillations about a
shared static resting position. The deformation body includes,
furthermore, a--most often annular--external edge segment, which is
adapted to be connected, with hermetic sealing, for example, by
material bonded connection, with a seat serving for mounting the
deformation body, and the sensor formed therewith, to a wall of a
tube, in such a manner that the deformation body covers and
hermetically seals an opening provided in the wall of the tube and
that the surface of the deformation body carrying the sensor blade
faces the fluid conveying lumen of the measuring tube, or of the
pipeline. Thus, the sensor blade protrudes inwardly into the lumen.
Since the deformation body is embodied typically membrane like, or
disc shaped, a thickness of the inner segment of the deformation
body carrying the sensor blade, equally as well bounded by the
outer edge segment, is most often very much less than a greatest
diameter of a surface of the segment bounded by the outer edge
segment. In order to achieve a sufficiently high measuring
sensitivity, namely a sufficiently high sensitivity of the sensor
to the pressure fluctuations to be registered, deformation bodies
of established measuring systems have typically a corresponding
diameter to thickness ratio, which lies, for instance, in the order
of magnitude of 20:1. As shown, for instance, in the above
referenced U.S. Pat. No. 6,352,000, sensor assemblies of the
previously indicated type can have, at times, additionally, a
balancing body, most often a rod-, plate- or shell shaped balancing
body, extending from a surface of the deformation body facing away
from the surface carrying the sensor blade. The balancing body
serves, especially, to compensate forces, and moments resulting
from movements of the sensor assembly, for example, as a result of
vibrations of the pipeline, and to prevent undesired movements of
the sensor blade resulting therefrom.
[0006] For the purpose of generating the sensor signal, the sensor
comprises, furthermore, a corresponding transducer element, for
example, a transducer element formed by means of a capacitor
mechanically coupled with the sensor assembly, or integrated
therein, or one formed by means of a piezo-stack serving as
piezoelectric transducer. The transducer element is adapted to
register movements of the deformation body, or of the, in given
cases, present, balancing body, corresponding to pressure
fluctuations and to modulate an electrical or optical carrier
signal accordingly.
[0007] The sensor assembly, i.e. the sensor formed therewith, is
connected on a side facing away from the fluid conveying lumen,
furthermore, with a transmitter electronics, typically a pressure-
and shock resistantly encapsulated, in given cases, also outwardly
hermetically sealed, transmitter electronics. Transmitter
electronics of industrial grade measuring systems have usually a
corresponding digital measuring circuit electrically connected with
the transducer element via connecting lines, in given cases, with
interposed electrical barriers and/or galvanic separation
locations, for processing the at least one sensor signal produced
by the transducer element and for producing digital measured values
for the measured value to be registered in each case, namely flow
velocity, volume flow rate and/or mass flow rate. The transmitter
electronics of industrially usable measuring systems established in
industrial measurements technology are usually accommodated in a
protective housing of metal and/or shock resistant synthetic
material and additionally most often also have external interfaces
conforming to an industrial standard, for example, DIN IEC 60381-1,
for communication with superordinated measuring--and/or control
systems, for example, formed by means of programmable logic
controllers (PLC). Such an external interface can be embodied, for
example, as a two-conductor connection of an electrical current
loop and/or some other interface compatible with established
industrial fieldbuses.
[0008] Particularly due to the relatively high diameter to
thickness ratios of the deformation body resulting from the
principle of measurement, conventional sensors of the type being
discussed--in the case of application of a high strength nickel
based alloy, such as e.g. Inconel 718 (Special Metals Corp.), as
material for the deformation body--can most often have a pressure
limit, namely a maximum permitted operating pressure, above which a
nonreversible plastic deformation of the sensor, especially its
deformation body, can occur. This pressure limit can be too low for
the extremely high pressures, at times, actually occurring in
certain applications. The situation can be such that even in the
case of only momentary, for instance impulse like, overloading, the
integrity of the respective measuring system, and the declared
accuracy of measurement, can no longer be assured. This, for
instance, also in the (hot-) steam treatments with fluid
temperatures of above 400.degree. C. actually to be expected for
the principle of measurement being discussed, in the case of which,
for example, so-called condensation induced, water hammers (CIWH)
in the region of the sensor can lead not only to extremely high
dynamic pressures of above 140 bar, but, also, at times, to very
non-uniform, asymmetric, pressure distributions within the fluid to
be measured, in such a manner that the pressure fluctuations then
acting on the sensor blade, measured in the detection direction,
have peak values of greater than 20 bar, and, as a result, to an
increased degree, corresponding irreversible deformations of the
sensor assembly, along with a failure of the measuring system, are
to be observed in such applications.
[0009] Based on the above, an object of the invention is to improve
the construction of sensor assemblies of the type being discussed,
especially sensors formed therewith, such that, as a result, they
have a higher pressure resistance, and a dependence of the pressure
resistance on the operating temperature enabling use in hot steam
treatments with steam temperatures of above 400 C and, at times,
impulse like, changing pressures with pressure spikes of above 140
bar.
[0010] For achieving the object, the invention resides in a sensor
assembly for a sensor, for example, a sensor for registering
pressure fluctuations in a Karman vortex street formed in a flowing
fluid, which sensor assembly comprises: [0011] a deformation body,
for example, a membrane like and/or disk shaped, deformation body,
having a first surface, an oppositely lying, second surface, for
example, a second surface at least partially parallel to the first
surface, and an outer edge segment, for example, an annular outer
edge segment and/or an outer edge segment provided with a sealing
surface; [0012] a sensor blade extending from the first surface of
the deformation body to a distal end, for example, a plate-shaped,
or wedge shaped, sensor blade, having a left side, first lateral
surface and a right side, second lateral surface; [0013] as well as
an overload protection apparatus extending from the edge segment of
the deformation body to a distal end and serving for protection of
the deformation body against plastic, i.e. irreversible,
deformation, with a support stirrup led with lateral separation
around the sensor blade as well as two stops held by the support
stirrup for limiting movement of the sensor blade, of which a first
stop is located on the left side of the sensor blade and a second
stop is located on the right side of the sensor blade. [0014] The
stops of the sensor assembly of the invention are additionally so
dimensioned and so arranged that an intermediate space formed
therebetween receives only a portion of the sensor blade, for
example, an edge located portion of the sensor blade. [0015] The
deformation body and the sensor blade of the sensor assembly of the
invention are, in turn, adapted to be excited to execute
oscillations for example, forced oscillations, about a shared
static resting position and, in such case, to be moved relative to
the overload protection apparatus, in such a manner that the sensor
blade executes pendulum-like movements elastically deforming the
deformation body, in the case of which the portion of the sensor
blade located within the intermediate space is moved alternately to
the left, namely in the direction toward the first stop, and to the
right, namely in the direction toward the second stop.
[0016] Moreover, the invention resides in a sensor for registering
pressure fluctuations in a flowing fluid, for example, for
registering pressure fluctuations in a Karman vortex street formed
in the flowing fluid, which sensor comprises such a sensor assembly
as well as a transducer element for generating a sensor signal, for
example, an electrical or optical, sensor signal, representing
movements of the sensor blade changing as a function of time, for
example, at least at times periodic movements of the sensor blade,
and/or deformations of the deformation body changing as a function
of time, for example, at least at times periodic deformations of
the deformation body.
[0017] Furthermore, the invention resides in a measuring system for
measuring at least one flow parameter, for example, a flow
parameter changeable as a function of time, for example, a flow
velocity and/or a volume flow rate, of a fluid flowing in a
pipeline, which measuring system comprises a sensor for registering
pressure fluctuations in the flowing fluid, for example, for
registering pressure fluctuations in a Karman vortex street formed
in the flowing fluid, as well as a measuring electronics, which is
adapted to receive the sensor signal and to process such, for
example, to generate measured values representing the at least one
flow parameter.
[0018] A further aspect the invention is use of such a measuring
system for measuring a flow parameter--, for example, a flow
velocity and/or a volume flow rate and/or a mass flow rate--of a
fluid, for example, a vapor or steam, flowing in a pipeline, for
example, a fluid having at least at times a temperature of greater
than 400.degree. C. and/or at least at times acting with a pressure
of greater than 140 bar on the deformation body and/or the sensor
blade of the sensor.
[0019] In a first embodiment of the sensor assembly of the
invention, it is provided that the overload protection apparatus
has a connecting element, for example, an annular connecting
element, on one end facing the edge segment of the deformation
body. [0020] Developing this embodiment of the invention, it is,
furthermore, provided that the connecting element as well as the
support stirrup are integral components of one and the same
monolithic, formed part. Alternatively, support stirrup and
connecting element can, for example, be connected or joined
together by material bonding, for example, welded together. [0021]
Moreover, the connecting element, the overload protection apparatus
and the edge segment of the deformation body can, for example, be
connected or joined together by material bonding, for example,
welded together.
[0022] In a second embodiment of the sensor assembly of the
invention, it is provided that deformation body, sensor blade and
overload protection apparatus are so dimensioned and arranged that,
in the case of sensor blade located together with the deformation
body in shared static resting position, the sensor blade contacts
neither the support stirrup nor either of the stops.
[0023] In a third embodiment of the sensor assembly of the
invention, it is provided that deformation body, sensor blade and
overload protection apparatus are so dimensioned and arranged that,
in the case of sensor blade together with the deformation body
located in shared static resting position, gaps are formed between
the sensor blade and each of the two stops, for example, in such a
manner that each of the gaps has a minimum gap breadth, which is
greater than 0.02 mm and/or less than 0.2 mm, and/or that the
sensor blade contacts neither of the stops.
[0024] In a fourth embodiment of the sensor assembly of the
invention, it is provided that deformation body, sensor blade and
overload protection apparatus are so dimensioned and arranged that,
in the case of sensor blade together with the deformation body
located in shared static resting position, a gap is formed between
the sensor blade and the support stirrup, for example, in such a
manner that the gap has a minimum gap breadth, which is greater
than 0.02 mm and/or that the sensor blade is not contacted by the
support stirrup.
[0025] In a fifth embodiment of the sensor assembly of the
invention, it is provided that deformation body, sensor blade and
overload protection apparatus are so dimensioned and arranged that,
in the case of sensor blade together with the deformation body
located in a shared first end position differing from the shared
static resting position, the sensor blade contacts the first stop,
but, for example, does not contact the support stirrup. [0026]
Developing this embodiment of the invention, it is, furthermore,
provided that deformation body, sensor blade and overload
protection apparatus are so dimensioned and arranged that, in the
case of sensor blade together with the deformation body in a shared
second end position differing from the shared static resting
position as well as also from the shared first end position, the
sensor blade contacts the second stop, but, for example, does not
contact the support stirrup. [0027] Moreover, the deformation body,
the sensor blade and the overload protection apparatus are,
furthermore, so dimensioned and arranged that both a deformation of
the deformation body corresponding to the first end position as
well as also a deformation of the deformation body corresponding to
the second end position are only elastic, for example,
linearly-elastic, thus the deformation of the deformation body is
not plastic.
[0028] In a sixth embodiment of the sensor assembly of the
invention, it is provided that the sensor blade has a projection,
for example, a terminal and/or pin-shaped projection, and that
deformation body, sensor blade and overload protection apparatus
are so dimensioned and arranged that the projection protrudes
inwardly into the intermediate space formed between the stops.
[0029] Developing this embodiment of the invention, it is,
furthermore, provided that the stops are provided by edge segments
of a recess in the support stirrup, for example, a recess formed as
a passageway or bore, and the intermediate space is formed by a
lumen of the recess surrounded by the edge segments.
[0030] In a seventh embodiment of the sensor assembly of the
invention, it is provided that the support stirrup is led at least
partially on a left side of the sensor blade.
[0031] In an eighth embodiment of the sensor assembly of the
invention, it is provided that the support stirrup is conveyed at
least partially on a right side of the sensor blade.
[0032] In a ninth embodiment of the sensor assembly of the
invention, it is provided that the support stirrup is led at least
partially on a front side of the sensor blade.
[0033] In a tenth embodiment of the sensor assembly of the
invention, it is provided that the support stirrup is led at least
partially on a rear side of the sensor blade.
[0034] In an eleventh embodiment of the sensor assembly of the
invention, it is provided that the overload protection apparatus is
formed by means of a single, monolithic, formed part.
[0035] In a twelfth embodiment of the sensor assembly of the
invention, it is provided that the first stop, the second stop as
well as the support stirrup are integral components of one and the
same monolithic, formed part.
[0036] In a thirteen embodiment of the sensor assembly of the
invention, it is provided that the stops are formed at least
partially by edge segments of a recess provided in the support
stirrup.
[0037] In a fourteenth embodiment of the sensor assembly of the
invention, it is provided that the intermediate space is formed at
least partially by a lumen of a recess provided in the support
stirrup.
[0038] In a fifteenth embodiment of the sensor assembly of the
invention, it is provided that the overload protection apparatus is
composed at least partially, for example, predominantly or
completely, of a metal, for example, a stainless steel, or a nickel
based alloy.
[0039] In a sixteenth embodiment of the sensor assembly of the
invention, it is provided that deformation body and overload
protection apparatus are composed of the same material.
[0040] In a seventeenth embodiment of the sensor assembly of the
invention, it is provided that deformation body and overload
protection apparatus components are one and the same, monolithic,
formed part for example, a cast monolithic part or one manufactured
by 3D laser melting.
[0041] In an eighteenth embodiment of the sensor assembly of the
invention, it is provided that deformation body and overload
protection apparatus are connected together by material bonding,
for example, welded, brazed or soldered together.
[0042] In a nineteenth embodiment of the sensor assembly of the
invention, it is provided that deformation body and sensor blade
are connected together by material bonding, for example, welded,
brazed or soldered together.
[0043] In a twentieth embodiment of the sensor assembly of the
invention, it is provided that the outer edge segment is adapted to
be connected, for example, by material bonding and/or hermetically
sealed, to a seat serving for mounting the deformation body on a
wall of a tube, for example, in such a manner that the deformation
body covers, for example, hermetically seals, an opening provided
in the wall of the tube, and/or in such a manner that the first
surface of the deformation body faces a lumen of the tube, such
that the sensor blade protrudes inwardly into the lumen
[0044] In a twenty first embodiment of the sensor assembly of the
invention, it is provided that at least one sealing surface, for
example, a surrounding and/or an annular like sealing surface, is
embodied in the outer edge segment.
[0045] In a twenty second embodiment of the sensor assembly of the
invention, it is provided that the deformation body is at least
partially, for example, predominantly or completely, composed of a
metal, for example, a stainless steel, or a nickel based alloy.
[0046] In a twenty third embodiment of the sensor assembly of the
invention, it is provided that the sensor blade is at least
partially, for example, predominantly or completely, composed of a
metal, for example, a stainless steel, or a nickel based alloy.
[0047] In a twenty fourth embodiment of the sensor assembly of the
invention, it is provided that deformation body and sensor blade
are composed of the same material.
[0048] In a twenty fifth embodiment of the sensor assembly of the
invention, it is provided that deformation body and sensor blade
are components of one and the same, monolithic, formed part, for
example, a casting or a part manufactured by 3D laser melting.
[0049] In a twenty-sixth embodiment of the sensor assembly of the
invention, it is provided that the support stirrup is U-shaped.
Alternatively, the support stirrup can have, for example, also a
V-shape or an L-shape.
[0050] In a first embodiment of the measuring system of the
invention, it is provided that an opening is embodied in the wall
of the tube, for example, an opening having a seat serving for
mounting the deformation body on the wall, and that the sensor is
inserted into the opening in such a manner that the deformation
body covers the opening, for example, hermetically seals such, and
that the first surface of the deformation body faces the lumen of
the tube, such that the sensor blade protrudes inwardly into the
lumen. [0051] Developing this embodiment of the invention, it is,
furthermore, provided that the opening has a seat serving for
mounting the deformation body on the wall. Embodied in the seat,
furthermore, can be at least one sealing surface, for example, a
surrounding sealing surface and/or an annular like, sealing
surface. Moreover, additionally embodied in the edge segment can be
at least one sealing surface, for example, a surrounding sealing
surface and/or an annular like, sealing surface, and the sealing
surface as well as the sealing surface of the seat can be adapted
for a hermetic sealing of the opening, for example, also with at
least one seal interposed.
[0052] In a first further development of the measuring system of
the invention, such further comprises a tube insertable into the
course of the pipeline and having a lumen, which is adapted to
convey the fluid flowing in the pipeline, wherein the sensor is
inserted into the tube in such a manner that the first surface of
the deformation body faces the lumen of the tube and the sensor
blade protrudes inwardly into the lumen. [0053] In a first
embodiment of the first further development of the measuring
system, it is, furthermore, provided that the sensor blade has a
length, measured as a minimum distance between a proximal end of
the sensor blade, namely an end bordering on the deformation body,
and a distal end of the sensor blade, namely an end remote from the
deformation body, i.e. the surface of the deformation body, wherein
the length is less than 95% of a caliber of the tube and/or greater
than half of the caliber. [0054] In a second embodiment of the
first further development of the measuring system, it is,
furthermore, provided that the overload protection apparatus has a
length, measured as a minimum distance between a proximal end of
the overload protection apparatus, namely an end bordering on the
deformation body, and a distal end of the overload protection
apparatus, namely an end remote from the deformation body, i.e. the
surface of the deformation body, which length is less than 95% of a
caliber of the tube and/or greater than half of the caliber.
[0055] In a second further development of the measuring system of
the invention, such further comprises a tube insertable into the
course of the pipeline and having a lumen, which is adapted to
convey the fluid flowing in the pipeline, wherein an opening is
embodied in the wall of the tube, especially an opening having a
seat serving for mounting the deformation body on the wall, and
wherein the sensor is inserted into the opening in such a manner
that the deformation body covers the opening, especially
hermetically seals it, and that the first surface of the
deformation body faces the lumen of the tube, such that the sensor
blade protrudes inwardly into the lumen. [0056] In a first
embodiment of the second further development of the measuring
system, it is, furthermore, provided that the sensor blade has a
length, measured as a minimum distance between a proximal end of
the sensor blade, namely an end bordering on the deformation body,
and a distal end of the sensor blade, namely an end remote from the
deformation body, i.e. its surface, wherein the length is less than
95% of a caliber of the tube and/or greater than half of the
caliber. [0057] In a second embodiment of the second further
development of the measuring system, it is, furthermore, provided
that the overload protection apparatus has a length, measured as a
minimum distance between a proximal end of the overload protection
apparatus, namely an end bordering on the deformation body, and a
distal end of the overload protection apparatus, namely an end
remote from the deformation body, i.e. its surface, which length is
less than 95% of a caliber of the tube and/or greater than half of
the caliber.
[0058] In a third further development of the measuring system of
the invention, such further comprises a bluff body arranged in the
lumen of the tube and adapted to bring about a Karman vortex street
in the flowing fluid.
[0059] A basic idea of the invention is to provide for the sensor
assembly of the invention a desired high nominal pressure
resistance also in the case of highly asymmetric pressure loading
of the sensor blade--especially asymmetric pressure loading,
wherein the pressure fluctuations acting on the sensor blade,
measured in the detection direction, have peak values of greater
than 20 bar, namely a positive pressure of greater than 20 bar on
the left side, first lateral surface of the sensor blade or with a
positive pressure of greater than 20 bar on the right side, second
lateral surface of the sensor blade--by limiting the maximum
possible deflections of the sensor blade at least in the detection
direction by means of an additional, overload protection apparatus
at least sectionally surrounding the sensor blade. The invention is
based, among other things, also on the surprising discovery that
while the supplementally arranged overload apparatus, in comparison
to conventional sensor assemblies, does, indeed, represent an extra
flow obstruction, its influence on the accuracy of measurement,
even in the case of design of the overload apparatus for the
previously indicated high loadings, especially even in the case of
condensation induced water hammers, is actually negligible.
[0060] An advantage of the invention is that it provides, not only
in very simple, equally as well very effective, manner, a
considerable improvement of the nominal pressure resistance of
sensors of the type being discussed, but also that this can be
achieved without thereby mentionably lessening the measuring
sensitivity, namely the sensitivity of the sensor to the pressure
fluctuations actually to be registered, or diminishing to an
intolerable extent the typically required (especially in industrial
application), high accuracy of measurement. A further advantage of
the invention is additionally also that the sensor assembly of the
invention can, in principle, be constructed in manner equal to that
used for known sensor assemblies of conventional sensors and
measuring system formed therewith. Moreover, the deformation body
and the sensor blade of the sensor assembly of the invention can
also, in principle, have the same construction and be manufactured
of the same materials as conventional membranes and sensor
blades.
[0061] The invention as well as advantageous embodiments thereof
will now be explained in greater detail based on examples of
embodiments, which are shown in the figures of the drawing. Equal,
including equally acting or equally functioning, parts are provide
in all figures with the equal reference characters; when
perspicuity requires or it otherwise appears sensible, already
mentioned reference characters are omitted in subsequent figures.
Other advantageous embodiments or further developments, especially
also combinations, of, firstly, only individually explained aspects
of the invention, will become evident, furthermore, from the
figures of the drawing and/or from the claims. The figures of the
drawing show as follows:
[0062] FIGS. 1, 2 schematically in different views, a measuring
system--here embodied as a vortex flow measuring device--with a
sensor and a measuring electronics for measuring at least one flow
parameter of a fluid flowing in a pipeline;
[0063] FIGS. 3a, 3b, 3c, 3d schematic, also partially sectioned,
views of a (first variant) of a sensor assembly for a sensor,
especially suitable for application in a measuring system according
to FIG. 1, or 2;
[0064] FIGS. 4a, 4b 4c, 4d schematically in two different,
sectioned, side views, a second variant of a sensor assembly for a
sensor, especially suitable for application in a measuring system
according to FIG. 1, or 2;
[0065] FIGS. 5a, 5b 5c, 5d schematically in two different,
sectioned, side views, a third variant of a sensor assembly for a
sensor, especially suitable for application in a measuring system
according to FIG. 1, or 2;
[0066] FIGS. 6a, 6b 6c, 6d schematically in two different,
sectioned, side views, a, fourth variant of a sensor assembly for a
sensor, especially suitable for application in a measuring system
according to FIG. 1, or 2; and
[0067] FIGS. 7a, 7b 7c, 7d schematically in two different,
sectioned, side views, a fifth variant of a sensor assembly for a
sensor, especially suitable for application in a measuring system
according to FIG. 1, or 2.
[0068] FIGS. 1 and 2 show an example of an embodiment for a
measuring system for measuring at least one flow parameter, in
given cases, also a flow parameter changeable as a function of
time, such as e.g. a flow velocity v and/or a volume flow rate V',
of a fluid flowing in a pipeline, for example, a hot gas,
especially having at least at times a temperature of greater than
400.degree. C., and/or at least at times a high pressure,
especially greater than 140 bar. The pipeline can be embodied, for
example, as a component of a heat supply network or a turbine
circulatory system, such that the fluid can be, for example, steam,
especially also saturated steam or superheated steam, or, for
example, also condensate drained from a steam line. Fluid can be,
however, for example, also a (compressed) natural gas or a biogas,
such that the pipeline can be, for example, also component of a
natural gas or a biogas plant or a gas supply grid.
[0069] The measuring system includes a sensor 1, which is provided,
and embodied, to register pressure fluctuations in the fluid
flowing in a principal flow direction past the sensor and to
transduce such into a sensor signal s1, for example, an electrical
or optical, sensor signal s1, corresponding to the pressure
fluctuations. As evident from the combination of FIGS. 1 and 2, the
measuring system comprises, furthermore, a measuring electronics
2--, for example, a measuring electronics 2 accommodated in a
pressure--and/or shock resistant protective housing 20. Measuring
electronics 2 is connected to the sensor 1 and communicates with
the sensor 1 during operation of the measuring system. Measuring
electronics 2 is adapted, especially, to receive the sensor signal
s1 and to process such, for example, to generate measured values
X.sub.M representing the at least one flow parameter, for example,
thus flow velocity v, or volume flow rate V'. The measured values
X.sub.M can, for example, be displayed on-site and/or
transmitted--by wire via connected fieldbus and/or wirelessly per
radio--to an electronic data processing system, for instance, a
programmable logic control unit (PLC) and/or a process control
station. The protective housing 20 for the measuring electronics 2
can be produced, for example, of a metal, for instance, a stainless
steel or aluminum, and/or by means of a casting method, such as
e.g. an investment casting--or a pressure casting method (HPDC); it
can, however, for example, also be formed by means of a plastic
formed part manufactured in an injection molding method.
[0070] Sensor 1 comprises, as well as also directly evident from
FIG. 2 and FIGS. 3a, 3b, 3c, 3d, in each case, or from a
combination of these figures, a sensor assembly 11, which is formed
by means of an, especially membrane like, or disk shaped,
deformation body 111 as well as a sensor blade 112 having a left
side, first lateral surface 112+ as well as a right side, second
lateral surface 112#. Sensor blade 112 extends from a first surface
111+ of the deformation body 111 to a distal (free) end, namely an
end remote from the deformation body 111 and its surface 111+.
Deformation body 111 includes, furthermore, a second surface 111#
lying opposite the first surface 111+ and, for example, at least
partially parallel to the first surface 111+, as well as an
external edge segment 111a, for example, an annular, external edge
segment 111a and/or an annular, external edge segment 111a equipped
with a sealing surface. Outer edge segment 111a has a thickness,
which--such as indicated in FIG. 2, or 3a, 3b, 3c, 3d--is
significantly greater than a minimum thickness of an inner segment
111b enclosed by the edge segment 111a--here namely an inner
segment 111b carrying the sensor blade 112.
[0071] Deformation body 111 and sensor blade 112 of the sensor
assembly 11 of the invention are, especially, adapted, to be
excited to execute oscillations, typically forced oscillations,
about a shared static resting position, in such a manner that the
sensor blade 112 executes in a detection direction--extending
essentially transversely to the above-referenced principal flow
direction--pendulum-like movements elastically deforming the
deformation body 111. The sensor blade 112 has, accordingly, a
breadth b (measured as a maximum extent in the direction of the
principal flow direction), which is significantly greater than a
thickness d of the sensor blade 112, measured as a maximum lateral
extent in the direction of the detection direction. In the example
of an embodiment illustrated in FIGS. 3a, 3b, 3c, 3d, the sensor
blade 112 is additionally embodied essentially wedge shaped; it
can, however, for example, also be embodied as a relatively thin,
planar plate, such as quite usual in the case of such sensor
assemblies, and sensors formed therewith.
[0072] Deformation body 111 and sensor blade 112 can, furthermore,
be, for example, components of one and the same monolithic, formed
part, which is produced, for example, by casting or by a generative
method, such as, for instance, 3D laser melting; deformation body
and sensor blade can, however, also be embodied as individual
parts, firstly, separated from one another, and only subsequently
connected together by material bonding, for example, welded, brazed
or soldered together, and, consequently produced from materials
correspondingly connectable together by material bonding.
Deformation body 111 can--such as quite usual in the case of such
sensor assemblies--be, at least partially, for example,
predominantly or completely, of a metal, such as e.g. stainless
steel, or a nickel based alloy. Likewise, also the sensor blade can
at least partially be made of a metal, for example, a stainless
steel, or a nickel based alloy; especially, the deformation body
111 and the sensor blade 112 can also be of the same material.
[0073] Besides the sensor assembly 11, the sensor comprises,
furthermore, a transducer element 12--, for example, a transducer
element 12 embodied as a piezoelectric transducer, a capacitive
transducer element 12 embodied as a component of a capacitor, or an
optical transducer element 12 embodied as a component of a
photodetector--for generating a signal changing as a function of
time--typically namely at least at times periodic--and representing
movements of the sensor blade, and, equally, a signal changing as a
function of time and representing deformations of the deformation
body 111, here also a signal serving as a sensor signal, for
example, in the form of a variable electrical voltage, or
correspondingly modulated laser light, modulated by the previously
indicated movements.
[0074] In an additional embodiment of the invention, the measuring
system comprises, furthermore, a tube 3 insertable into the course
of the previously indicated pipeline and having a lumen 3'
enveloped by a--, for example, metal--wall 3* of the tube. Tube 3
extends from an inlet end 3+ to an outlet end 3# and is adapted to
convey the fluid flowing in the pipeline. Sensor 1 is additionally
inserted in the tube in such a manner that the first surface of the
deformation body 111 faces the lumen 3' of the tube, consequently
such that the sensor blade protrudes inwardly into the lumen. In
the example of an embodiment shown here, there is provided on the
inlet end 3+, as well as also on the outlet end 3#, furthermore, in
each case, a flange serving for establishing a leak free flange
connection with, in each case, a corresponding flange on an
inlet--, and outlet, side, line segment of the pipeline.
Furthermore, tube 3 can be embodied, such as in FIG. 1 or 2, to be
essentially straight, for example, as a hollow cylinder with a
circularly shaped cross section, in such a manner that the tube 3
has an imaginary, straight, longitudinal axis L imaginarily
connecting the inlet end 3+ and the outlet end 3#. Sensor 1 is in
the example of an embodiment shown in FIGS. 1 and 2 inserted from
the exterior through an opening 3'' formed in the wall into the
lumen of the tube and affixed in the region of the opening--, for
example, also releasably--externally on the wall 3*, and, indeed,
such that the surface 111+ of the deformation body 111 faces the
lumen 3' of the tube 3, such that the sensor blade 112 protrudes
inwardly into the lumen. Especially, sensor 1 is so inserted into
the opening 3'' that the deformation body 111 covers the opening
3'', and hermetically seals it. The opening can, for example, be so
embodied that it--such as quite usual in the case of measuring
systems of the type being discussed--has an (inner-) diameter,
which lies in a range between 10 mm and about 50 mm.
[0075] In an additional embodiment of the invention, a seat 3a
serving for mounting the deformation body on the wall 3* is
embodied in the opening 3''. Sensor 1 can, in such case, be affixed
to the tube 3, for example, by material bonded connecting,
especially by welding, soldering, or brazing, of deformation body
111 and wall 3*; it can, however, for example, also be connected
releasably with the tube 3, for example, by a screwed attachment.
Embodied in the seat 3a can be, furthermore, at least one sealing
surface, for example, also a surrounding, or annular, sealing
surface, which is adapted, by interacting with the deformation body
111 and a, in given cases, provided, for example, annular or
washer-shaped, sealing element, correspondingly to seal the opening
3''. Particularly for the case, in which the sensor assembly is to
be inserted into the seat 3a and connected releasably with the tube
3, also the edge segment 111a of the deformation body 111 can, in
advantageous manner, furthermore, be provided with a sealing
surface, for example, a sealing surface corresponding with the
sealing surface provided, in given cases, in the opening 3'' and/or
an annular sealing surface.
[0076] In the example of an embodiment shown here, the measuring
system is especially embodied as a vortex flow measuring device
having a bluff body 4 arranged in the lumen of the tube 3--here
namely located upstream of the sensor 1--, and serving for
effecting a Karman vortex street in the flowing fluid. Sensor and
bluff body are, in such case, especially, so dimensioned and
arranged that the sensor blade 112 protrudes inwardly into such a
region in the lumen 3* of the tube, and into the fluid conveyed
therein, which is occupied during operation of the measuring system
regularly by a (steady-state) Karman vortex street, so that the
pressure fluctuations registered by means of the sensor 1 are
periodic pressure fluctuations caused by oppositely sensed vortices
shed from the bluff body 4 with a shedding rate
(.about.1/fv.sub.tx), and the sensor signal s1 has a signal
frequency (.about.fv.sub.tx) corresponding to the shedding rate of
the vortices. In the example of an embodiment shown here, the
vortex flow measuring device is additionally embodied as a
measuring system in compact construction, in the case of which the
measuring electronics 2 is accommodated in a protective housing 20
held on the tube--, for example, by means of a neck shaped
connection nozzle 30.
[0077] In an additional embodiment of the invention, sensor 1 and
tube 3 are, furthermore, so dimensioned that a length I of the
sensor blade 112, measured as a minimum distance between a proximal
end of the sensor blade 112, namely an end bordering on the
deformation body 111, and the distal end of the sensor blade 112,
is greater than half a caliber DN of the tube 3 and less than 95%
of the caliber DN. The length l can, for example,--such as quite
usual in the case of comparatively small calibers of less of than
50 mm--also be so selected that the distal end of the sensor blade
112 has only a very small minimum distance from the wall 3* of the
tube 3. In the case of tubes with comparatively large calibers of
50 mm or more, the sensor blade 112 can--such as quite usual in the
case of measuring systems of the type being discussed, and as well
as also evident from FIG. 2--, for example, also be embodied
significantly shorter than half a caliber of the tube 3.
[0078] As already mentioned, the sensor assembly, the sensor formed
therewith, and the measuring system formed therewith, are
especially provided to be applied at measuring points, where
momentarily extremely high dynamic pressures can occur in the fluid
to be measured, for example, due to condensation induced water
hammering (CIWH), in such a manner that the pressure fluctuations
acting in the detection direction on the sensor 1 have peak values
of greater than 20 bar, namely with a positive pressure of greater
than 20 bar on the left side, first lateral surface of the sensor
blade or with a positive pressure of greater than 20 bar on the
right-side, second lateral surface of the sensor blade, along with
correspondingly high asymmetric loadings of the sensor blade and
the deformation body. For preventing overloading of the deformation
body as a result of pressure fluctuations acting asymmetrically on
the sensor blade, especially also with peak values of greater than
20 bar, or, associated therewith, plastic or otherwise irreversible
deformation of the sensor assembly, especially of the deformation
body, the sensor assembly 1 of the invention includes, as well as
also schematically shown in FIGS. 2, 3c, 3d, in each case,
furthermore, an overload protection apparatus 113 extending from
the edge segment 111a to a distal end, namely an end remote from
the edge segment 111a, and from the deformation body. Other
variants of overload protection apparatus are also shown in FIGS.
4a-d, 5a-d, 6a-d, and 7a-d. The overload protection apparatus 113
is formed by means of a support stirrup 113a led with lateral
separation around the sensor blade 112 as well as by means of two
stops 113b, 113c for the sensor blade 112. Stops 113b, 113c are
held by the support stirrup. Of the stops, a first stop 113b is
placed on the left side of the sensor blade 112 and a second stop
113c on the right side of the sensor blade 112. The stops 113b,
113c are additionally so dimensioned and arranged that an
intermediate space 113' formed therebetween receives only a
selected, for example, edge, terminal and/or pin--, or plug shaped,
first portion 112a of the sensor blade 112, equally as well does
not receive, i.e. leaves free, a second portion 112b of the sensor
blade 112 extending between the portion 112a and the first surface
111+ of the deformation body 111. Moreover, the deformation body
111 and the sensor blade 112 are adapted, in performing the
previously indicated oscillations around the shared static resting
position, to be moved relative to the overload protection apparatus
113 in such a manner that along with the pendulum-like movements of
the sensor blade 112 executed in such case, its portion 112a
located within the intermediate space 113' is moved alternately to
the left, namely in the direction toward the first stop 113b, and
to the right, namely in the direction toward the second stop 113c.
The overload protection apparatus 113 can, for example, at least
partially, especially., however, also predominantly or completely,
be made of a metal, such as, for instance, a stainless steel, or a
nickel based alloy. Additionally, advantageously also deformation
body 111 and overload protection apparatus 113, in given cases,
also the sensor blade, can be manufactured of the same
material.
[0079] Furthermore, the two stops as well as the support stirrup
can, for example, also be integral components of one and the same
monolithic, formed part, for example, also in such a manner that
the entire overload protection apparatus is formed by means of a
single, monolithic, formed part. The monolithic, formed part can
be, for example, a casting or a formed part, especially of a metal,
manufactured by a generative method, such as e.g. 3D laser
melting.
[0080] Deformation body 111 and overload protection apparatus 113
can, however, for example, be joined together, namely connected
together by material bonding, especially be welded, or soldered,
together. In an additional embodiment of the invention particularly
helpful for joining deformation body 111 and overload protection
apparatus 113 together, the overload protection apparatus 113 has a
connecting element 113d on an end facing the edge segment 111a of
the deformation body 111. The connecting element 113d can, such as,
among other things, also directly evident from a combination of
FIG. 3a-d, be, for example, ring-shaped. Additionally, the
connecting element 113d and the edge segment 111a can be arranged
such that they are coaxially. In an additional embodiment of the
invention, the connecting element 113d and the edge segment 111a
are additionally connected together by material bonding, especially
welded together. Likewise, also the support stirrup 113a and the
connecting element 113d can be connected together by material
bonding, especially welded together; connecting element 113d and
support stirrup 113a can, however, for example, also be integral
components of one and the same, monolithic, formed part.
[0081] Deformation body 111, sensor blade 112 and overload
protection apparatus 113 are, furthermore, so dimensioned and so
arranged that, in the case of sensor blade together with the
deformation body located in their shared static resting position,
these contact neither the support stirrup, nor either of the stops.
In order to assure that, on the one hand, the sensor blade
(together with the deformation body) located in the static resting
position actually contacts neither of the stops, and, on the other
hand, the pendulum-like movements of the sensor blade 112 deforming
the deformation body 111 elastically can nevertheless have a
maximum deflection sufficient for registering the pressure
fluctuations, i.e. for ascertaining a shedding rate of vortices
causing periodic pressure fluctuations, the deformation body 111,
the sensor blade 112 and the overload protection apparatus 113,
according to an additional embodiment of the invention, are,
furthermore, so dimensioned and arranged that, at least in the case
of sensor blade located in the static resting position, a
sufficiently large gap is formed between this and each of the two
stops, especially in such a manner that each of the gaps has, in
each case, a minimum gap breadth, which is greater than 0.02 mm.
Moreover, it is, furthermore, provided that deformation body,
sensor blade and overload protection apparatus are so dimensioned
and arranged that, in the case of sensor blade located in the
static resting position, a sufficiently large gap is formed between
this and the support stirrup, especially in such a manner that the
gap has a minimum gap breadth, which is greater than 0.02 mm,
especially greater than 0.05 mm.
[0082] For the purpose of implementing a protection of the
deformation body against plastic, i.e. irreversible, deformation,
for instance, as a result of pressure fluctuations acting
asymmetrically on the sensor blade, or a protection of the sensor
assembly formed by means of the deformation body against
destruction resulting from such pressure fluctuations, the
deformation body 111, the sensor blade 112 and the overload
protection apparatus 113 according to an additional embodiment of
the invention are, furthermore, so dimensioned and arranged that,
in the case of sensor blade located together with the deformation
body 111 in a shared first end position differing from the shared
static resting position, the sensor blade contacts the first stop
113b, especially, however, does not contact the support stirrup
113a. Moreover, the deformation body 111, the sensor blade 112 and
the overload protection apparatus 113 according to an additional
embodiment of the invention are additionally also so dimensioned
and arranged that, in the case of sensor blade 112 located together
with the deformation body in a shared second end position differing
from the shared static resting position, as well as also from the
shared first end position, the sensor blade contacts the second
stop 113c, especially, however, does not contact the support
stirrup 113a. Especially, the deformation body, the sensor blade
and the overload protection apparatus are, furthermore, so
dimensioned and arranged that both a deformation of the deformation
body corresponding to the first end position as well as also a
deformation of the deformation body corresponding to the second end
position is elastic, especially linearly-elastic, so that the
deformations effected by the pendulum-like movements of the sensor
blade are completely reversible. This can be assured for sensor
assemblies with typical dimensions in the case of the sensor blade
and the deformation body, for example, directly by selecting the
above-referenced gap formed in the case of sensor blade located in
static resting position between such and the support stirrup to be
less than 0.2 mm, as measured at least in the detection direction.
Particularly for the purpose of forming a sufficiently large
intermediate space 113', namely one enabling the previously
indicated gap, the support stirrup 113 according to an additional
embodiment of the invention is, furthermore, so embodied that it
has a thickness d2, measured as a maximum lateral extent in the
direction of the detection direction, which is not less than the
above-referenced thickness d of the sensor blade 112. Alternatively
or supplementally, the support stirrup 113 can also be so embodied
that at least one of the two subsections of the support stirrup 113
carrying the stops 113b, 113c has the thickness d2 and/or that this
subsection of the support stirrup 113 has a thickness, measured as
a lateral extent in the detection direction, which is less than the
thickness d of the sensor blade 112, equally as well greater than a
thickness of the portion 112a of the sensor blade 112 accommodated
by the intermediate space, measured as its lateral extent in the
detection direction. Furthermore, the support stirrup 113a can
have, for example, a square cross section, in such a manner that
breadth b2 of the support stirrup 113a is, for instance, as large
as its thickness d2, respectively, for instance, also lies in the
order of magnitude of the thickness d of the sensor blade 112; the
cross section can, however, also, for example, be rectangular
shaped, such that the breadth b2 of the support stirrup 113a can
also be selected somewhat greater or also somewhat less than its
thickness d2, respectively the thickness d of the sensor blade
112.
[0083] In an embodiment of the invention, the support stirrup 113a
is at least partially led on the rear side, here namely, in the
principal flow direction, downstream of the sensor blade.
Alternatively or supplementally, the support stirrup can at least
partially be led also on the front side, here namely, in the
principal flow direction, upstream of the sensor blade. In another
embodiment of the invention, the overload protection apparatus 113
is so embodied and so arranged that the support stirrup 113a is led
at least partially on the left side of the sensor blade 112 and/or
that the support stirrup 113a is led at least partially on the
right side of the sensor blade 112. The support stirrup 113a, and
the overload protection apparatus 113 formed therewith, can
accordingly, for example, be so embodied that the support stirrup
113a, such as directly evident, for instance, in FIGS. 3a-d, FIGS.
4a-d or FIGS. 5a-d, in each case, and from a combination of FIGS.
3a-d, 4a-d, and 5a-d, in each case, has an essentially U-shaped
outline. Particularly for the case, in which the support stirrup
113a is led both on the left side of the sensor blade 112 as well
as also on the right side of the sensor blade 112, the support
stirrup 113a can, for example, also, as evident in FIGS. 6a-d, and
their combination, have a V-shaped outline. For the other case, in
which the support stirrup 113a is led partially on the rear side or
partially on the front side of the sensor blade, the support
stirrup can, such as, for instance, in FIG. 7a-d, also have an
L-shaped outline.
[0084] For the purpose of forming the portion 112a of the sensor
blade 112 accommodated by the intermediate space 113' of the
overload protection apparatus 113, the sensor blade 112 includes,
according to an additional embodiment of the invention, a
projection, especially a cylindrical or cuboid-shaped projection,
i.e. the portion 112a is formed by the projection. Additionally,
the deformation body, the sensor blade and the overload protection
apparatus are, as well as also evident from a combination of FIGS.
3a-d, FIGS. 5a-d or 6a-d, so dimensioned and arranged that the
projection (112a) protrudes inwardly into the intermediate space
113' formed between the stops. A greatest diameter of the
projection can, for example, be so selected that it corresponds, as
well as also evident from a combination of FIGS. 3a-d, FIGS. 5a-d
or 6a-d, for instance, to the thickness d. The diameter can,
however, for example, also be selected less than the previously
indicated thickness d of the sensor blade 112, for example, also
such that the above-referenced thickness d2 of the support stirrup
113a can, in given cases, even be equal to or less than the
thickness of the sensor blade.
[0085] In the case of this embodiment of the invention, the two
stops 113b, 113c can, furthermore, be formed by edge segments of a
recess provided in the support stirrup 113a and the intermediate
space 113' by a lumen of the recess surrounded by the edge
segments, in such a manner that the recess serves practically as a
seat and the projection as a plug occupying the seat with
sufficient play, namely play enabling the previously indicated
pendulum-like movements of the sensor blade, respectively that
recess and projection have a loose fit, for example, with
noticeable to ample play relative to the fitting system "Standard
Bore" (DIN EN ISO 286-2:2010). The recess can, for example, be a
passageway or bore provided in the support stirrup 113a; the recess
can, however, for example, also be embodied as an elongated hole in
the support stirrup, or as a blind hole in the support stirrup. In
the case of the blind hole, an open end correspondingly faces the
sensor blade 112 for the purpose of accommodating the projection.
In another embodiment of the invention, it is provided that the
recess forming the intermediate space 113', such as indicated, for
example, also in FIGS. 4a-d, and FIGS. 7a-d, is essentially groove
shaped, respectively essentially trough shaped. Moreover, the
deformation body, the sensor blade and the overload protection
apparatus can, as well as also evident from FIGS. 4a-d, and FIGS.
7a-d, in such case, furthermore, be so dimensioned and arranged
that the recess provided in the support stirrup 113a, and the stops
113b, 113c formed therewith and the intermediate space 113' formed
therewith, in each case, extend essentially over the entire breadth
b of the sensor blade 112, and that the portion 112a of the sensor
blade accommodated by the intermediate space 113' has a breadth
corresponding to its breadth b.
[0086] For compensating forces and/or moments resulting from
possible movements of the sensor assembly--, for instance, as a
result of vibration of the above-referenced pipeline connected to
the tube--, and for preventing undesired movements of the sensor
blade, or of the deformation body 111, resulting therefrom, namely
movements corrupting the sensor signal s1, the sensor assembly 11
includes, according to an additional embodiment of the invention,
furthermore, a balancing body 114, for example, a rod-, plate- or
sleeve-shaped, balancing body 114, extending from the second
surface 111# of the deformation body 111. Balancing body 114 can
additionally also serve as a holder for transducer element 12 or
also as a component of the transducer element 12, for example, as a
movable electrode of a capacitor forming the (capacitive)
transducer element. The balancing body 114 can, for example, be of
the same material as the deformation body and/or as the sensor
blade, for example, a metal. For example, the balancing body 114
can namely be produced from a stainless steel, or a nickel based
alloy. In an additional embodiment of the invention, deformation
body 111 and balancing body 114 are connected together by material
bonding, for example, welded, brazed or soldered together.
Consequently, balancing body 114 and deformation body 111 can be
manufactured of materials connectable together by material bonding.
Alternatively, deformation body 111 and balancing body 114 can,
however, also be components of one and the same monolithic, formed
part, for example, also in such a manner that sensor blade 111,
deformation body 112 and balancing body 114 are components of the
formed part. Sensor blade 112 and balancing body 114 can,
furthermore--, as well as also evident from FIGS. 3c and 3d--be
arranged aligned with one another, in such a manner that a
principal axis of inertia of the sensor blade 112 coincides with
the lengthened principal axis of inertia of the balancing body 114.
Alternatively or supplementally, the balancing body 114 and the
deformation body 111 can additionally be so positioned and oriented
relative to one another that a lengthened principal axis of inertia
of the deformation body 111 coincides with a principal axis of
inertia of the balancing body 114. Moreover, sensor blade 112,
balancing body 114 and deformation body 111 can also so positioned
and oriented relative to one another that--such as, for example,
also evident from a combination of FIGS. 2, 3a, 3b, 3c and 3d--a
principal axis of inertia of the sensor assembly 11 extends
parallel both to a principal axis of inertia of the sensor blade
112 as well as also a principal axis of inertia of the balancing
body 114, as well as also a principal axis of inertia of the
deformation body 111 or coincides both with the principal axis of
inertia of the sensor blade as well as also the principal axis of
inertia of the balancing body, as well as also with the principal
axis of inertia of the deformation body.
* * * * *